The present invention is related to a printing method for window blind slats, comprising three printing rollers that are equidistantly spaced out in a transverse direction with one growth-ring printing area and two fine-texture printing areas alternatively arranged and precisely formed at the corresponding lengthwise and widthwise positions of the sequentially aligned printing rollers thereon so that blind slats can be synchronically printed with complete wood grain pattern of growth-ring pictures and fine-texture pictures on the surfaces thereof, efficiently providing a speedier printing method and ensuring an accurate control of the quality of each blind slat so as to boost the competitive power as well as to achieve a standardized manufacturing thereof.
Please refer to FIG. 1. A convention method of printing wood grain pattern onto window blind slats 10 comprises a printing roller 20 having a growth-ring printing area 21 arranged at the middle section thereon, and two fine-texture printing areas 22 distributed at both lateral sections thereon. The conventional printing method thereof includes steps as follows:
First, three blind slats 10, 10′, 10′″ are located side by side before the printing roller 20 already coated with coloring material, and then transported to move through the printing roller 20 with growth-ring pictures 11′ printed onto the middle blind slat 10′ and fine-texture pictures 12, 12″ printed onto both lateral blind slats 10, 10″ thereon respectively.
Second, the three blind slats 10, 10′, 10″ with the growth-ring pictures 11′ or the fine-texture pictures 12′, 12″ respectively printed thereon are withdrawn and then relocated in front of the printing roller 20 with switched positions before going through the same aforementioned printing process again. After three rounds of the repeated printing process thereof, the blind slats 10, 10′, 10″ will be respectively printed with complete wood grain pattern and finished with growth-ring pictures 11, 11′, 11″ and fine-texture pictures 12, 12′, 12″ disposed thereon.
There are some disadvantages to such conventional printing method for window blind slats. First, although the printing roller 20 can serve to print the three blind slats 10, 10′, 10″ simultaneously, the three blind slats 10, 10′, 10″ must be constantly switched in positions to repeat the same printing process over and over again so as to have complete wood grain pattern printed onto the surfaces thereof, which is rather complicated and time-consuming, and thus makes the printed slats uncompetitive on the market. Second, when the slats 10 are repeatedly withdrawn and then printed in the process thereof, part of the growth-ring pictures 11 or the fine-texture pictures 12 may subject to the phenomena of drying-up or color-binding, which can make the wood grain pattern printed onto the slats 10 dye in different shade or incompletely interrupted as shown in A of FIG. 2. Thus, defective slats can easily come up and the quality of the slats 10 is difficult to control in the conventional printing method thereof.